The aims of this proposal are to study various aspects of corneal physiology and aqueous dynamics. Specifically, in the cornea, a) The relationship between bicarbonate and water movement across the endothelium, b) the effects of drugs, inhibitors and chemicals on endothelial bicarbonate movement, including variations in Na ion and Cl ion, ouabain, amiloride, thiocyanate, ethacrynic acid, SITS, dipyridamole, glucose and lactate; c) examine the rate of bicarbonate movement as a function of cell margin length in regenerating rabbit endothelium where the cell size becomes smaller after complete covering of endothelial lesions; d) the interrelationships between bicarbonate, CO2 and pH in sealed chambers using micro pCO2 and micro pH electrodes, as well as using gradients of these parameters and examining the effect of applied voltages; e) develop new methodology for the preparation of endothelium plus Descemets membrane; f) Examine the relationship between photooxidation reactions and bicarbonate fluxes across the endothelium as modified by 1) hydroxyl ion generators; 2) peroxidase inhibitors or free radical scavengers and 3) lipid peroxidation; g) Study the effects of various lipids on endothelial structure and function; and the modification of photooxidation or drug effects, h) Study vehicle effects on ocular drug penetration. In aqueous dynamics, a) study the effects of ascorbic acid and transported or non-transported amino acids on isolated ciliary epithelial secretion rates, b) Measure the hydrostatic pressure in the major circle of the iris, c) Use in vitro and in vivo approaches to determine the role of the pigment epithelium in aqueous humor formation.